With the development of human society, communication devices and identification devices have become more and more widely used. The use of smart cards and associated identification devices has brought greatly improved safety and convenience to people's travel.
A smart card, also referred to as an IC card, is a portable plastic card with an IC chip adhered thereon or embedded therein. The card includes a microprocessor, an I/O interface and a memory, which provides functions of computing, access control and storage of data. The size and connecting terminals of the card are specified by relevant ISO standards such as ISO7810. Common smart cards include telephone IC cards, identification IC cards, and some transport tickets and memory cards.
The smart card includes a card body and a smart card module mounted on the card body. The smart card module includes a circuit board and electronic components (such as a chip) mounted on the circuit board. Due to its light weight, small thickness, the circuit board has been widely used in various electronic devices, such as cell phones, notebook computers, tablet PCs and liquid crystal displays (LCDs).
In currently available circuit board products, an adhesive layer between the chip and the circuit board has strong flowability and is inclined to flow randomly, which may result in some area in the pad region has no adhesive layer and some area outside of the pad region has the adhesive layer. This may cause poor adhesion between the chip and the circuit board and reduced reliability of the circuit board.